Partial support is requested for the fourth and fifth FASEB Summer Conferences, "Mobile Elements in Mammalian Genomes" which will be held in Snowmass, CO, July 5-10, 2009. The objective of the meeting is to bring together a diverse group of investigators with a common interest in mobile DNA to discuss recent advances in how mobile elements have impacted and continue to influence the functional expression and evolution of mammalian genomes. The program comprises all aspects of mobile DNA including bioinformatic, biochemical, evolutionary, and population genetic studies on mammalian transposable elements, as well as work to exploit transposable elements for saturation mutagenesis and gene delivery. Comparative genomics provides strong evidence for mobile DNA amplification, repression and extinction in evolutionary time. The 1000 genomes project as well as a wealth of new studies on mobile element association with epigenetics and gene networks represent a particular highlight of this year's meeting. This timely conference will facilitate the sharing of exciting new findings, experimental challenges, and outstanding questions in this rapidly evolving field among students, post- doctoral trainees, and junior and senior principal investigators. This is particularly valuable in a field, such as mobile elements, that does not conform to Mendelian genetic principles, and therefore has unique needs in terms of analysis and approaches. PUBLIC HEALTH RELEVANCE: Mobile elements have played, and continue to play a major role in shaping the structure and function of the mammalian genome. Retrotransposition insertions throughout the genome can lead to gene disruption, modified expression of adjacent genes, and transduction of neighboring DNA. Recent studies show that this process is actively continuing within the human population. These interspersed repeated sequences may give rise to novel regulatory networks, or provide a substrate for homologous recombination of mispaired sequences, leading to gene duplication, deletion, exon shuffling and chromosome translocation. All of the dynamic events caused by the presence and movement of mobile DNA in the human genome may lead to disease, including meiotic failure and infertility, inherited genetic diseases such as hemophilia and muscular dystrophy, and somatic diseases such as breast and colon cancer.